Mermaid Anecdote

From Lady Gregory's Visions and Beliefs in the West of Ireland, told by John Corley.
 

There is no luck if you meet a mermaid and you out at sea, but storms will come, or some ill will happen.

There was a ship on the way to America, and a mermaid was seen following it, and the bad weather began to come. And the captain said, "It must be some man in the ship she's following, and if we knew which one it was, we'd put him out to her and save ourselves." So they drew lots, and the lot fell on one man, and then the captain was sorry for him, and said he'd give him a chance till tomorrow. And the next day she was following them still, and they drew lots again, and the lot fell on the same man. But the captain said he'd give him a third cance, but the third day the lot fell on him again.

And when they were going to throw him out he said, "Let me alone for a while." And he went to the end of the ship and he began to sing a song in Irish, and when he sang, the mermaid began to be quiet and to rock like as if she was asleep. So he went on singing till they came to America.